Refrigeration



. R. H. BEMAN July 9, 1940.

REFRIGERATION Filed Aug. 11, 1931' 3 Sheets-Sheet l v INVENTOR.EANSOMH-BEMAN ATTORNEY.

R; H. BEMAN REFRIGERATION July 9, 1940.

Filed Aug. 11, 1931 3 Sheets-Sheet 2 57 TOR. 7 By EANs M HBEMANATTORNEY.

Patented July 9, 1949 UNITED STATES REFRIGERATION Ransom H. Beman,Detroit, Mich assignor, by

mesnc assignments, to Nash-Kelvinator c poration,

Detroit, Maryland Mich,

a corporation of Application August 11, 193i, Serial No. 556,420

6 Claims.

This invention relates to household and other .refrigeration apparatusand particularly to the construction and arrangement of refrigerantevaporating units and metering devices employed in such apparatus.

An object of the invention is to provide a refrigerant evaporating unitwhich may be constructed of sheets of metal welded together and bent toform a compartment for the reception of ice trays and with whichstructure a refrigerator may be cooled by air circulating by naturaldraft or otherwise against the exterior surface thereof.

Another object of the invention is to provide a refrigerant evaporatorembracing a header or disengaging space wherein evaporated refrigerantmay collect in a region above tl e liquid refrigerant level and whichheader may be constructed in a complete and operative form before thesheets are bent to form an enclosure.

Another object of the invention is to provide a refrigerant evaporatorwhich may be manufactured in the form of a relatively flat plate-likestructure which thereafter may be bent into any desired form.

Another object of the invention is to provide a sheet metal evaporatorstructure having a plurality of parallel passages therein for thedistribution of refrigerant liquid and to which structure liquidrefrigerant is supplied in a relatively low region.

Another object of the invention is to provide a refrigerant evaporatingunit which may be supplied with liquid by a high side float type-of me-5 tering device located in the interior of a compartment toberefrigerated and supported directly by the evaporating unit.

Another object of the invention is to provide a brine receiving vesselfor a sheet metal refrig- 40 erant evaporating unit which vesselwhenproperly filled with liquid will tend to increase the period betweencycles of operation of the refrigq crating mechanism.

For a better understanding of the invention reference may now be had tothe accompanying drawings forming a part of this specification, inwhich:

Figure 1 is a front elevational view of a refrigerator with a portion ofthe door and'machine compartment thereof broken away so that therefrigerating mechanism thereof is visible;

Figure 2 is a cross sectional view of the refrigerant evaporating unitillustrated by Figure 1;

Figure 3 is a fragmentary longitudinal sectional view of the refrigerantevaporator illustrated by Figures 1 and 2 and taken substantially online 3-3 of Figure 2;

Figure 4 illustrates another form of the invention in which arefrigerant evaporating unit is suspended directly from the refrigeratorlining by flanges formed at the extremities of'a metallic sheet fromwhich the evaporating unit is constructed;

Figure 5 is a fragmentary cross sectional view of the evaporating unitstructure illustrated by 10 Figure 4 and taken substantially on line 55thereof I Figure 6 is a fragmentary cross sectional view of arefrigerator illustrating another form of evaporator embracing theinvention disclosedherein;

Figure '7 is a fragmentary cross sectional view of the evaporator andrefrigerator disclosed by Figure 6; A

Figure 8 is a plan view of an evaporator at one stage in itsconstruction;

Figure 9 is an end elevational view partly in cross section of theevaporator disclosed by Figure 8 and embracing a phantom figure showinghow the evaporator is formed;

Figure 10 is a cross sectional view of the incomplete evaporatorillustrated by Figure 8 and taken substantially on line lll-l0 thereof;

' Figure 11 illustrates a portion of the evaporator element shown byFigure 9 and taken substantially on line H--ll thereof.

Referring more particularly to the drawings,. Figure 1 illustrates aninsulated cabinet l6 having an opening I! for the reception of foodproducts etc. to'be refrigerated and which is normally closed by a doorl8 suspended by hinges l9 and securedin position by a latch 2|. An,upper wall 22 of the refrigerator l6, which may or may not be removable,is adapted to support a refrigerant condensing unit 23, the principalelements of which are a motor 24, a compressor 26 and a condenser 21. r

The motor 24 is provided with a grooved pulley, not shown, which drivesthe compressor 26 by means of a belt 28 operatively associated with 45 acombined compressor driven pulley and fly wheel 29. The drive pulley ofthe motor 24 also has secured thereto a fan 2| adapted to discharge ablast of air against the condenser 21 for cooling the latter. The motor24, compressor 26, and condenser 21 all are rigidly secured to ametallic base plate 3| which rests upon the upper refrigerator wall 22.Compressed refrigerant vapor delivered by the compressor 26 isdischarged through a conduit 32 into an upper portion of th condenser 21from whence it is in turn discharged through a conduit 33 into a highside float 34 located in the interior of the refrigerator "5.

The float casing 36 is provided with a threaded opening at its lowerextremity engaging an annular coupling 31 which in turn engages athreaded opening in a refrigerant evaporator 38. Brackets 39 securedrigidly to the upper wall 22 of the refrigerator iii in turn are securedto the evaporator 38 thus supporting the latter and the float mechanism33. The refrigerant vapor evaporated in the evaporating unit 33 isexhausted therefrom through a conduit 4| to the suction side of thecompressor 26.

The float valve mechanism 34 comprises essen-- tially a casing 36,hereinbefore referred to, which is cylindrical in formation and threadedat its upper extremity to receive a cover 42 to which the conduit 33 isconnected by a coupling 63. The cover 62 has a centrally disposedopening 43 which provides a communicating passage between the interiorof the conduit 33 and the casing 36 and through which refrigerant liquidcondensed in the condenser 21 is discharged into the casing 36 of thefloat valve mechanism 34.

Disposed within the interior of the casing 36 and adapted to be buoyedup by the liquid refrig-' erant therein is a relatively light float 36having an axiallyarranged passage 41 therein. An upper portion of thepassage t! is occupied by a needle valve 68 secured rigidly to the floatby flanges as. The lower portion of the passage 37 is adapted to receiveslidably the upper extremity of a tubular member- 49, the lower end ofwhich is permanently secured to the casing 37 by threads formed thereonwhich engage the threaded lower portion of the casing. The upper end ofthis member is provided with an annular seat 5! adapted to cooperatewith the needle 48 to close the passage through the member 39 andconsequently the communication between the interior of the casing 38 andthe interior of the evaporator 33.

It is apparent that liquid refrigerant discharged from the conduit 33into the casing 36 will gradually fill the latter to such an extent thatthe float 36 will be moved upwardly and the needle 48 moved away fromits seat to permit any amount of refrigerant in excess of that requiredto lift the float to flow downwardly through the passage in the tubularmember 39 and into the evaporator 33.

The evaporator 38 is provided with a' capillary expansion tube liquidfeeding device 52 which is connected in parallel with the high sidefloat 3:1, one of the ends of the tube communicating with the interiorof the casing 33 on one side of the needle valve 48 while the oppositeend thereof communicates with the evaporator as indicated at 56. It -isapparent that the liquid or gaseous refrigerant always will flow throughthe expansion tube 52 but inasmuch as the latter is of very small crosssectional area and of great length, the amount of refrigerant which cantravel therethrough will be considerably less than the amount of liquidnormally supplied by the condensing unit. Under such circumstancesliquid will gradually accumulate in the interior of the casing 33 untilit elevates the float and the surplus thereof flows through the tubularmember 39.

When the condensing unit is not in operation the expansion tube 53 willentirely drain the liquid from the casing 36 into the evaporator 38 andthen will discharge gaseous refrigerant until-such time as the pressureis reduced to a considerable degree. In other words, the expansion tube52 serves as an unloading device for the condensing unit 23 and hence itis possible to employ a motor having a relatively low starting torque.

The evaporating unit 38 consists essentially of interior and exteriormetallic sheets 55 and 51 respectively which preferably are assembled toproduce an evaporator according to the method illustrated by Figures 8,9, l0 and 11. The exterior sheet 57, for example, is provided throughoutits length with a plurality of parallel depressions or corrugations 58which terminate in a semi-cylindrical depression, header or manifold 59extending across the sheet midway between the extremities thereof. Inother words, the depression 59 intersects all of the depressions 58midway between their opposite ends. The parallel depressions or passages51 and the transversely disposed passage 59 all are formed, for example,byemploying a die while the sheet is substantially planular. The sheet56 is provided with relatively large semi-cylindrical depressions,passages or headers GI and 62 adjacent the opposite ends of the sheetand extending transversely thereof, relative to the parallel passages 58in the sheet 51. The sheet 56 also is provided with a relatively smalldepression 63 on one of its edges and intermediate the ends of the sheetwhich cooperateswlth the end of the transverse depression 59 in thesheet 51 to provide a relatively round opening for the reception of aninternally threaded ring 64.

Thus preformed, the sheets 53 and 57 are disposed one upon the other andwelded around their peripheries and along the contacting portionsthereof between the depressions 58 in the sheet 51. The flat unit thusassembled is then bent in regions designated by the numerals 66 and 611to provide a water freezing compartment of the usual form.

Intermediate the opposite ends of the headers 6| and 62 are formedflanged openings 68 and 39 the extremities of which are welded togetherafter the evaporator is formed to provide a means of communicationbetween the two headers. Brackets 1! may be welded on the inside shell53 along thelength of the evaporator in such manner as to providesupporting means for metallic plates or shelves l2 on which ice trays 13are positioned. Ebullators it for initiating evaporation of refrigerantliquid are adapted to be positioned if desired in the depression orchannel 55 With which the lower extremities of the parallel passages 58communicate. In the operation of the evaporator relatively warmrefrigerant liquid when discharged into the channel 59 immediately comesin contact with relatively cold refrigerant in the evaporator andwith'the ebullators 14 after which its tempera" ture is rapidly reducedby evaporation. The refrigerant vapor bubbles so formed flow upwardlythrough the passages 58, and violently agitate evaporating unit directlyfrom the upper insulated wall 22. The hangers terminate in flanges i6bent either outwardly or inwardly as desired and which are secured to asheet metal lining l1 of the cabinet by bolts I8. The flanges and thelining, however, are separated either at inter- I vals or-entirelythroughout the length thereof by rubber or other insulating spacingmaterial or. strips 19. In this form of the invention the extremities ofthe evaporator are not bent inwardly as in the form previouslydescribed, but the headers 6| and 62 are connected together by a tube 8|inserted and welded in the flanges 68 and B9. The tube 8| in thisinstance communicates with the suction line 4| through which refrigerantvapor is exhausted from the evaporating unit to the condensing unit. Ahigh side float 82 in this instance and principally for the purpose ofillustration is located outsideof therefrigerator lining and isconnected to thefiange 84 at the lower extremity of the evaporator by aliquid line 83. A shelf, not shown, for supporting an ice tray in thisevaporator is adapted to rest upon a pair of projections 84 formed inthe inner shell 56 longitudinally of. the evaporator.

In the form of the invention illustrated by Figures 6 and '7 the innershell 56 is constructed from a perfectly fiat piece of sheet metal whilethe outer shell is constructed from a similar sheet in which acontinuous depression or passage is formed. When these sheets areassembled, welded and bent into the proper shape another shell 88 havingparallel, passages or depressions 81 may be positioned about thestructure and welded thereto at itsperiphery. The region between theshells and188 may be employed for the reception of. a suitable-holdoverliquid, such as brine, for example, which maybe introduced thereinthrough openings, 8'lnormally closed by caps 88. This type ofevaporator,-which normally is employed in a dry refrigerating system, isprovided with a coupling-'89 at one end of the sinuous passage formedibetween thesheets 56 and-51 and to which the suction line 4| is at-.tached. The opposite extremity of the sinuous passage is provided withasimilar coupling 9| to which an automatic or a thermostatically con- 51and as it proceeds through the passage it absorbs heat and is changedinto refrigerant vapor before reaching the end to which the suction line4| is attached.

While in this specification a number of forms of evaporators and otherelements of refrigerating systems have been disclosed and also a methodor process of constructing evaporators, it is apparent that theinvention may assume other forms or embodiments within the scope of. theappended'claims.

I claim:

1. Refrigerating apparatus comprising insulated walls forming a storagechamber to be cooled, evaporating means for cooling said chamher, saidmeans comprising a pair of nested sheet metal casings,-spaced apart butjoined at their peripheries and at spaced intervals intermediate theirperipheries to provide a relatively shallow refrigerant chamben-one ofsaid casings extending beyond the confines of the-other, and beingsecured to one of the insulating' walls for supporting the evaporatingmeans. r

2. A. sheet metal evaporator comprising an 3 outer one piece shell andan inner one piece shell bent to form the side and bottom walls of asharp freezing chamber, arcuate depressions formed parallel to andspaced from the ends of one of said shells and also spaced from thefront and back edges of said shell, said arcuate depressions cooperatingwith the other shell to form headers located at theaends of the shellsbut adjacent each other due to the bent form of the evaporator, embossedportions formed in one sheet and extending around the side. and bottomwalls of the evaporator-and connecting the two headers,

and a connecting T forming a common refrigerant conduit between said twoheaders.

- 3. A sheet metal evaporator comprising an headers located at the endsof the shells butadjacent each other due to the bent form of theevaporator, embossed portions formed in one sheet and extending aroundthe side and bottom walls of the evaporator and connecting the twoheaders, said shells being welded together around the front and backperipheries and across'the end peripheries, and a connecting T forming acommon refrigerant conduit between said two headers.

4.. A sheet metal evaporator comprising an outer one piece shell and aninner one piece shell bent to form the side and bottom walls of a sharpfreezing chamber, arcuate depressions formed parallel to and spaced fromthe ends of one of said shells and also spaced from the frontand backedges of said shell, said arcuate depressions cooperating with the othershell to form headers located'at the ends of the shells but adjacenteachother'due to the bent form of the evaporator, embossed portionsformed'in one sheet and extending around the side and bottom walls ofthe evaporator and connecting the two headers, said shells being weldedtogether around the front and back peripheries and across the endperipheries, a connecting T' forming a' common re. frigerant outletbetween said two headers and an inlet connection formed at the bottom ofthe evaporator and communicating with the embossed portions in thebottom wall of the evaporator.

-.5. A sheet metal evaporator comprising an outer shell and an innershell each formed substantially in the flat and bent after-welding toform, a U-shaped sharp freezing chamber, an embossed-portion in oneshell consisting of an arcuate depression spaced :from an edge of theshells and cooperating with the other shell to forma headenanembossedportion in one shell spaced from adifiere'nt edge of said shells andconsisting of ..an.arcuate depression cooperating with the other shellto form another header, em

bossed portionsin' one shell and-forming refrigerant passageways leadingfrom each header and extending over the exposed surface of the .shellformingv the sharp-freezing chamber, said 6. A sheet metal evaporatorcomprising an outer one piece shell and an inner one piece shell bent toform a sharp freezing chamber, an embossed portion in one shellconsisting of an arcuate depression spaced from an edge of the shellsand cooperating with the other shell to forma header, an embossedportion in one shell spaced from a difierent edge of said shells andconsisting of an arcuate depression cooperating with the other shell toform another header, embossed portions in one shell and formingrefrigerant

